碳酸盐分解反应的产物是氧化物以气体状态放出，属于（）反应。
参考答案：可逆吸热
Security was such a major concern at the G8 Summit that no journalists could approach the meeting zone without ________ the special pass.[ ]
A. producing
B. issuing
C. commanding
D. involving
以下属于临时水工建筑物的是( )。
A．导流墙
B．挡水大坝
C．电站厂房
D．围堰
